This invention relates to certain new semiconductor devices which incorporate multilayer optical interference regions, e.g., quarter-wave high reflector stacks (HR).
A wide variety of semiconductor devices depend upon appropriate reflectance/transmittance properties of certain regions therein. These include lasers, bistable optical devices, optical modulators, photodetectors, etc. Conventionally, reflectance and transmittance are achieved by the use of dielectric and metallic surfaces. Typically, these surfaces are incorporated into the device by mechanical or even chemical means, typically to form a nonmonolithic structure. See, e.g., Gibbs et al, Appl. Phys. Lett. 41 (3), 1 Aug. 1982, 221; Chemla et al, Appl. Phys. Lett. 42 (10), 15 May 1983, 864; U.S. Pat. No. 3,813,605; U.S. Pat. No. 3,758,797; U.S. Pat. No. 3,626,257; U.S. Pat. No. 4,477,824; with respect to bistable devices, and a wide variety of references with respect to other such optical devices including lasers, e.g., as described in U.S. Pat. Nos. 4,591,889; 4,438,446; 3,893,148; 4,205,331; 4,439,782; 4,270,094.
The use of multilayers of semiconductor materials to achieve the desired reflectance/transmittance has also been disclosed. Such layers have been incorporated into optical devices monolithically. The layers include both lattice matched semiconductor binaries or alloys, and lattice mismatched (strained) semiconductor binaries or alloys (SLS). Furthermore, individual layers of the multilayers may comprise superlattices (matched or mismatched) of very thin layers wherein quantum size effects are present. See, e.g., Gourley, "Superlattices and Microstructures", Vol. 1, No. 3, 1985, 227; Ogura et al, Japanese Journal of Applied Physics, Vol. 22, No. 2, February 1983, L112 (the use of top and bottom multilayer HRs surrounding an active GaAs region to form a surface-emitting laser diode); U.S. Pat. No. 4,309,670 (discussing such multilayer regions at one or both ends of a Fabry-Perot cavity), as well as discussions of this invention which appear in the literature, e.g., Gourley et al, Appl. Phys. Lett. 49 (9), 1 Sept. 1986, 489. See also Gourley et al, Appl. Phys. Lett. 49 (5), 4 Aug. 1986, 242 for a discussion of the use of such multilayer HR stacks as optical interference filters, e.g., for use in conjunction with a photodiode. Multilayer HR regions based on mismatched materials are discussed by Gourley et al (4 Aug. 1986).